Water-based drilling fluid compositions and methods for drilling subterranean wells

ABSTRACT

According to one or more embodiments of the present disclosure, water-based drilling fluids may include an aqueous base fluid and one or more additives. In embodiments, water-based drilling fluids may include a lubricant blend including at least oleic acid and palmitoleic acid. The sum of the volume percent of the oleic acid and palmitoleic acid may be from 0.1 vol. % to 10 vol. % of the total volume of the water-based drilling fluid. In embodiments, water-based drilling fluids may include a lesser melting point fraction of jojoba oil in an amount of from 0.1 vol. % to 10 vol. % relative to the total volume of the water-based drilling fluid. At least 90% of the lesser melting point fraction of jojoba oil may have a melting point less than or equal to 15° C. Methods for drilling subterranean wells with the water-based drilling fluids are also disclosed.

BACKGROUND Field

The present disclosure relates to natural resource well drilling and,more specifically, to water-based drilling fluid compositions andmethods for drilling subterranean wells.

Technical Background

Drilling operations, for example, drilling a new wellbore forhydrocarbon extraction, may include the practice of continuouslycirculating a drilling fluid, also referred to as a drilling mud,through the wellbore during the operation. The drilling fluid may bepumped through the drill string to the bottom of the wellbore, where thedrilling fluid then flows upwardly through an annular space between thewellbore wall and the drill pipe and finally, returns to the surface andflows out of the wellbore where it may be recovered. During drilling,solids, such as portions of the drilled geological formation referred toas cuttings, may be transported by the drilling fluid from at or nearthe bottom of the wellbore to the surface. After its return to thesurface, the drilling fluid may be mechanically or chemically treated toremove captured solids from the drilling fluid before recirculation backthrough the wellbore.

SUMMARY

One objective of a drilling fluid may be the reduction of frictionbetween the drill string and the casing or the wellbore wall by actingas a lubricating medium between the metal-metal interface and themetal-mudcake interface while drilling. Some conventional water-baseddrilling fluids may have poor lubricating properties and, thus, may havea much greater coefficient of friction compared to oil-based drillingfluids. This is one of the major technical limitations of water-baseddrilling fluids compared to oil-based drilling fluids. To minimize thefrictional resistance or coefficient of friction value of water-baseddrilling fluids, lubricating additives may be incorporated into thedrilling fluids. However, many of these conventional additives havelimited applicability. For example, some conventional additives have alimited capacity to reduce the coefficient of friction of drillingfluids in downhole operations. Additionally, some conventional additiveslack the requisite thermal and chemical stability. Furthermore, someconventional additives are poorly biodegradable, toxic, or not“ecologically-friendly” and, as such, have restricted applications forecologically sensitive environments. Additionally, some conventionaladditives lack sufficient stability in relatively cold temperatures(such as, 60 degrees Celsius (° C.) or less, 30° C. or less, or 15° C.or less). For example, while conventional additives may operate aseffective lubricants at warmer temperatures (such as, at least 60° C.),these lubricants may be susceptible to solidifying in cold temperatures.As such, these lubricants may lose effectiveness during storage, duringdelays in operation, or during operations that occur in coldtemperatures.

Accordingly, there are ongoing needs for improved water-based drillingfluid compositions and methods for drilling subterranean wells. Thecompositions and methods of the present disclosure include a water-baseddrilling fluid that includes a lubricant blend. The lubricant blend may,for example, reduce the coefficient of friction of drilling fluids whilealso minimizing negative impact to the surrounding environment. Thelubricant blend may also effectively operate in cold temperatures (suchas 60° C. or less, 30° C. or less, or 15° C. or less). As a result, thewater-based drilling fluids of the present disclosure may provideoperability in cold environments, and may have superior lubricationproperties when compared to some water-based drilling fluids withoutlubricants and water-based drilling fluids incorporating conventionallubricants.

According to one or more embodiments of the present disclosure, awater-based drilling fluid may include an aqueous base fluid, one ormore additives, and a lubricant blend including at least oleic acid andpalmitoleic acid. The sum of the volume percent of the oleic acid andpalmitoleic acid may be from 0.1 volume percent (vol. %) to 10 vol. % ofthe total volume of the water-based drilling fluid.

According to one or more additional embodiments of the presentdisclosure, a water-based drilling fluid may include an aqueous basefluid, one or more additives, and a lesser melting point fraction ofjojoba oil in an amount of from 0.1 vol. % to 10 vol. % relative to thetotal volume of the water-based drilling fluid. At least 90 percent (%)of the lesser melting point fraction of jojoba oil may have a meltingpoint less than or equal to 15° C.

According to one or more additional embodiments of the presentdisclosure, a method for drilling a subterranean well may includeoperating a drill in a subterranean formation in the presence of awater-based drilling fluid. The water-based drilling fluid may includean aqueous base fluid, one or more additives, and a lubricant blendcomprising at least oleic acid and palmitoleic acid. The sum of thevolume percent of the oleic acid and palmitoleic acid may be from 0.1vol. % to 10 vol. % of the total volume of the water-based drillingfluid.

According to one or more additional embodiments of the presentdisclosure, a method for drilling a subterranean well may includeoperating a drill in a subterranean formation in the presence of awater-based drilling fluid. The water-based drilling fluid may includean aqueous base fluid, one or more additives, and a lesser melting pointfraction of jojoba oil in an amount of from 0.1 vol. % to 10 vol. %relative to the total volume of the water-based drilling fluid. At least90% of the lesser melting point fraction of jojoba oil may have amelting point less than or equal to 15° C.

Additional features and advantages of the technology described in thepresent disclosure will be set forth in the detailed description thatfollows, and in part will be readily apparent to those skilled in theart from the description or recognized by practicing the technology asdescribed in this disclosure, including the detailed description thatfollows, as well as the claims.

DETAILED DESCRIPTION

The present disclosure is directed to water-based drilling fluidcompositions and, additionally, to methods for drilling a subterraneanwell using such water-based drilling fluid compositions. A subterraneanformation is the fundamental unit of lithostratigraphy. As used in thepresent disclosure, the term “subterranean formation” may refer to abody of rock that is sufficiently distinctive and continuous from thesurrounding rock bodies that the body of rock can be mapped as adistinct entity. A subterranean formation may be sufficiently homogenousto form a single identifiable unit containing similar geologicalproperties throughout the subterranean formation, including, but notlimited to, porosity and permeability. A single subterranean formationmay include different regions, where some regions include hydrocarbonsand others do not. To extract hydrocarbons from the hydrocarbon regionsof the subterranean formation, production wells are drilled. Thewellbore of production wells may serve to connect hydrocarbon regions ofthe subterranean formation to the surface and enable hydrocarbons totravel from the subterranean formation to the surface. As used in thepresent disclosure, the term “wellbore” may refer to the drilled hole orborehole, including the openhole or uncased portion of the well.

According to one or more embodiments, to drill a subterranean well, adrill string is inserted into a pre-drilled hole and rotated to cut intothe rock at the bottom of the hole, producing cuttings. Drilling fluids,also referred to as drilling muds, may be pumped down through the drillstring during drilling to remove cuttings from the bottom of thesubterranean well. Drilling fluids may lift cuttings away from thebottom of the subterranean well when recirculated back to the surface.Drilling fluids may also serve a number of additional functions as well.For example, drilling fluids may also provide hydrostatic pressure inthe subterranean well sufficient to support the sidewalls of thesubterranean well. This hydrostatic pressure may prevent the sidewallsfrom collapsing and caving in on the drill string as well as preventfluids present in the subterranean formation from flowing into thesubterranean well during drilling.

In one or more embodiments, the present disclosure is directed towater-based drilling fluids that include an aqueous base fluid one ormore additives and a lubricant blend. In embodiments, the lubricantblend may include at least oleic acid and palmitoleic acid such that thesum of the volume percent of the oleic acid and palmitoleic acid may befrom 0.1 vol. % to 10 vol. % of the total volume of the water-baseddrilling fluid. In embodiments, the lubricant blend may include a lessermelting point fraction of jojoba oil in an amount of from 0.1 vol. % to10 vol. % relative to the total volume of the water-based drillingfluid. At least 90% of the lesser melting point fraction of jojoba oilmay have a melting point less than or equal to 15° C. Embodiments of thepresently disclosed water-based drilling fluids may be formulated toprovide improved lubricity. This formulation may have, in one or moreembodiments, the same or a reduced coefficient of friction when comparedto conventional lubricants suitable for water-based drilling fluids,while also being suitable for use in relatively cold temperatures (forexample, 60° C. or less, 30° C. or less, or 15° C. or less).

As stated previously in the present disclosure, the water-based drillingfluid may include an aqueous base fluid. As used in the presentdisclosure, the term “aqueous” may refer to a fluid or solution thatincludes water as the major constituent. In embodiments, the aqueousbase fluid may include at least one of fresh water, salt water, brine,municipal water, formation water, produced water, well water, filteredwater, distilled water, seawater, or combinations of these. The brinemay include at least one of natural and synthetic brine, such assaturated brine or formate brine. Without being bound by any particulartheory, it is believed that brine may be used to create osmotic balancebetween the water-based drilling fluid and the subterranean formation.

In embodiments, the aqueous base fluid may include water containingorganic compounds or salt. Without being bound by any particular theory,salt or other organic compounds may be incorporated into the aqueousbase fluid to control the density of the water-based drilling fluid.Increasing the saturation of the aqueous base fluid by increasing thesalt concentration or the level of other organic compounds in theaqueous base fluid may increase the density of the water-based drillingfluid. Suitable salts include but are not limited to alkali metalchlorides, hydroxides, or carboxylates. For example, in embodiments theaqueous base fluid may include sodium, calcium, cesium, zinc, aluminum,magnesium, potassium, strontium, silicon, lithium, chlorides, bromides,carbonates, iodides, chlorates, bromates, formates, nitrates, sulfates,phosphates, oxides, fluorides, or combinations of these.

In embodiments, the water-based drilling fluid may include an aqueousbase fluid in an amount of from 25 volume percent (vol. %) to 99 vol. %relative to the total volume of the water-based drilling fluid. Forexample, the water-based drilling fluid may include an aqueous basefluid in an amount of from 25 vol. % to 95 vol. %, from 25 vol. % to 85vol. %, from 25 vol. % to 75 vol. %, from 25 vol. % to 65 vol. %, from25 vol. % to 55 vol. %, from 25 vol. % to 45 vol. %, from 25 vol. % to35 vol. %, from 35 vol. % to 99 vol. %, from 35 vol. % to 95 vol. %,from 35 vol. % to 85 vol. %, from 35 vol. % to 75 vol. %, from 35 vol. %to 65 vol. %, from 35 vol. % to 55 vol. %, from 35 vol. % to 45 vol. %,from 45 vol. % to 99 vol. %, from 45 vol. % to 95 vol. %, from 45 vol. %to 85 vol. %, from 45 vol. % to 75 vol. %, from 45 vol. % to 65 vol. %,from 45 vol. % to 55 vol. %, from 55 vol. % to 99 vol. %, from 55 vol. %to 95 vol. %, from 55 vol. % to 85 vol. %, from 55 vol. % to 75 vol. %,from 55 vol. % to 65 vol. %, from 65 vol. % to 99 vol. %, from 65 vol. %to 95 vol. %, from 65 vol. % to 85 vol. %, from 65 vol. % to 75 vol. %,from 75 vol. % to 99 vol. %, from 75 vol. % to 95 vol. %, from 75 vol. %to 85 vol. %, from 85 vol. % to 99 vol. %, from 85 vol. % to 95 vol. %,or from 95 vol. % to 99 vol. % relative to the total volume of thewater-based drilling fluid.

As stated previously in the present disclosure, the water-based drillingfluid may include a lubricant blend. Lubricant blends may be used toincrease the lubricity (that is, decrease the coefficient of friction)of the water-based drilling fluid, decrease friction between the drillstring and the wellbore during drilling operations, or both. A decreaseof the coefficient of friction of the water-based drilling fluidcontaining the lubricant may provide a reduction in friction experiencedbetween the drilling components and the wellbore, such as the drillstring and the wellbore. The coefficient of friction may be measured inaccordance with a standard lubricity coefficient test. A lubricitytesting device commonly used by those in the drilling fluid industry(for example, OFI Testing Equipment, Inc. (OFITE), Houston, Tex.) may beutilized for measuring the coefficient of friction. In embodiments, thewater-based drilling fluid may include a lubricant blend in an amountsufficient for the water-based drilling fluid to achieve a coefficientof friction of from 0.01 to 0.15. For example, the water-based drillingfluid may include a lubricant blend in an amount sufficient for thewater-based drilling fluid to achieve a coefficient of friction of from0.01 to 0.12, from 0.01 to 0.09, from 0.01 to 0.06, from 0.01 to 0.03,from 0.03 to 0.15, from 0.03 to 0.12, from 0.03 to 0.09, from 0.03 to0.06, from 0.06 to 0.15, from 0.06 to 0.12, from 0.06 to 0.09, from 0.09to 0.15, from 0.09 to 0.12, or from 0.12 to 0.15.

In embodiments, the lubricant blend may include one or more fatty acids.As presently described, the lubricant blend may include a substantialmajority of or all of the fatty acids in the water-based drilling fluidinto which the lubricant blend may be incorporated. For example, thelubricant blend may include greater than or equal to 90%, greater thanor equal to 95%, greater than or equal to 99% or greater than or equalto 99.9% of the fatty acids in the water-based drilling fluid into whichthe lubricant blend may be incorporated. In embodiments, the lubricantblend may include long-chain fatty acids. As used in this disclosure,the term “long-chain fatty acid” refers to carboxylic acids that have analiphatic tail of from 13 carbon atoms to 21 carbon atoms. That is, along-chain fatty acid is a non-aromatic carboxylic acid that includes amain chain or “backbone” of from 13 carbon atoms to 21 carbon atoms,excluding branched sidechains. For example, palmitic acid(CH₃(CH₂)₁₄COOH) is a fatty acid that has an aliphatic tail of 16 carbonatoms and stearic acid (CH₃(CH₂)₁₆COOH) is a fatty acid that has analiphatic tail of 18 carbon atoms. Long-chain fatty acids may have analiphatic tail that is saturated or unsaturated, straight chain(unbranched) or branched, unsubstituted or heteroatom-substituted, orcombinations of these. Fatty acids may enhance the capacity of thelubricant blend to decrease the coefficient of friction of thewater-based drilling fluid. When fatty acids are homogenously dispersedwithin the water-based drilling fluid, the fatty acids may improve theinterface penetration capacity of the water-based drilling fluid tocreate a thin but strong lubricating film on the surfaces of thedrilling components.

In embodiments, the lubricant blend may include oleic acid, palmitoleicacid, or both. In embodiments, the sum of the volume percent of theoleic acid and the palmitoleic acid may be from 0.1 vol. % to 10 vol. %of the total volume of the water-based drilling fluid. For example, thesum of the volume percent of the oleic acid and the palmitoleic acid maybe from 0.1 vol. % to 8 vol. %, from 0.1 vol. % to 6 vol. %, from 0.1vol. % to 4 vol. %, from 0.1 vol. % to 2 vol. %, from 2 vol. % to 10vol. %, from 2 vol. % to 8 vol. %, from 2 vol. % to 6 vol. %, from 2vol. % to 4 vol. %, from 4 vol. % to 10 vol. %, from 4 vol. % to 8 vol.%, from 4 vol. % to 6 vol. %, from 6 vol. % to 10 vol. %, from 6 vol. %to 8 vol. %, or from 8 vol. % to 10 vol. % of the total volume of thewater-based drilling fluid. In embodiments, the molar ratio of oleicacid to palmitoleic acid present within the lubricant blend may be from25:1 to 50:1. For example, the molar ratio of oleic acid to palmitoleicacid present within the lubricant blend may be from 25:1 to 45:1, from25:1 to 40:1, from 25:1 to 35:1, from 25:1 to 30:1, from 30:1 to 50:1,from 30:1 to 45:1, from 30:1 to 40:1, from 30:1 to 35:1, from 35:1 to50:1, from 35:1 to 45:1, from 35:1 to 40:1, from 40:1 to 50:1, from 40:1to 45:1, or from 45:1 to 50:1.

In embodiments, the oleic acid of the lubricant blend, the palmitoleicacid of the lubricant blend, or both, may be derived from jojoba oil. Asused in the present disclosure, the term “derived” may refer to theprocessing of jojoba oil to produce a lubricant blend that includesoleic acid, palmitoleic acid, or both. For example, the lubricant blendmay include or consist essentially of a lesser melting point fraction ofjojoba oil. As used in the present disclosure, a “lesser melting pointfraction” may refer to the portion of jojoba oil that remains in aliquid phase at a particular temperature. Jojoba oil is the oilextracted from the seeds of the jojoba plant (Simmondsia chinensis) andis composed almost entirely of mono-esters of long-chain fatty acidswith only small amounts of triglyceride esters. As previously stated,long-chain fatty acids may enhance the capacity of the lubricant blendto reduce the coefficient of friction of the water-based drilling fluid.However, the majority of the fatty acids of jojoba oil (for example,gondoic acid and erucic acid) have melting points greater than 15° C. Asa result, jojoba oil readily forms solids at relatively mildtemperatures (for example, from 20° C. to 25° C.). These solidifiedfatty acids may fail to provide an effective increase in lubricity ofthe water-based drilling fluid. Without being bound by any particulartheory, it is believed that the solid particles may prevent theformation of a lubricating film on the surfaces of the drillingcomponents. In embodiments, at least 90% of the lesser boiling pointfraction of jojoba oil may have a melting point less than or equal to15° C. For example, at least 90% of the lesser melting point fraction ofjojoba oil may have a melting point less than or equal to 12° C., lessthan or equal to 9° C., less than or equal to 6° C., less than or equalto 3° C., or less than or equal to 0° C. Additionally, in embodiments atleast 92%, at least 94%, at least 96%, at least 98%, or at least 99% ofthe lesser boiling point fraction of jojoba oil may have a melting pointless than or equal to 15° C. In embodiments, the water-based drillingfluid may include the lesser melting point fraction of jojoba oil in anamount of from 0.1 vol. % to 10 vol. % relative to the total volume ofthe water-based drilling fluid. For example, the water-based drillingfluid may include the lesser melting point fraction of jojoba oil in anamount of from 0.1 vol. % to 8 vol. %, from 0.1 vol. % to 6 vol. %, from0.1 vol. % to 4 vol. %, from 0.1 vol. % to 2 vol. %, from 2 vol. % to 10vol. %, from 2 vol. % to 8 vol. %, from 2 vol. % to 6 vol. %, from 2vol. % to 4 vol. %, from 4 vol. % to 10 vol. %, from 4 vol. % to 8 vol.%, from 4 vol. % to 6 vol. %, from 6 vol. % to 10 vol. %, from 6 vol. %to 8 vol. %, or from 8 vol. % to 10 vol. % relative to the total volumeof the water-based drilling fluid.

In embodiments, the lesser melting point fraction of jojoba oil mayinclude oleic acid, palmitoleic acid, or both. In embodiments, thelesser melting point fraction of jojoba oil may include oleic acid in anamount of from 75 vol. % to 99 vol. % relative to the total volume ofthe lesser melting point fraction of jojoba oil. For example the lessermelting point fraction of jojoba oil may include oleic acid in an amountof from 75 vol. % to 95 vol. %, from 75 vol. % to 90 vol. %, from 75vol. % to 85 vol. %, from 75 vol. % to 80 vol. %, from 80 vol. % to 99vol. %, from 80 vol. % to 95 vol. %, from 80 vol. % to 90 vol. %, from80 vol. % to 85 vol. %, from 85 vol. % to 99 vol. %, from 85 vol. % to95 vol. %, from 85 vol. % to 90 vol. %, from 90 vol. % to 99 vol. %,from 90 vol. % to 95 vol. %, or from 95 vol. % to 99 vol. % relative tothe total volume of the lesser melting point fraction of jojoba oil. Inembodiments, the lesser melting point fraction of jojoba oil may includepalmitoleic acid in an amount of from 1 vol. % to 25 vol. % relative tothe total volume of the lesser melting point fraction of jojoba oil. Forexample, the lesser melting point fraction of jojoba oil may includepalmitoleic acid in an amount of from 1 vol. % to 20 vol. %, from 1 vol.% to 15 vol. %, from 1 vol. % to 10 vol. %, from 1 vol. % to 5 vol. %,from 5 vol. % to 25 vol. %, from 5 vol. % to 20 vol. %, from 5 vol. % to15 vol. %, from 5 vol. % to 10 vol. %, from 10 vol. % to 25 vol. %, from10 vol. % to 20 vol. %, from 10 vol. % to 15 vol. %, from 15 vol. % to25 vol. %, from 15 vol. % to 20 vol. %, or from 20 vol. % to 25 vol. %relative to the total volume of the lesser melting point fraction ofjojoba oil. In embodiments, the molar ratio of oleic acid to palmitoleicacid present within the lesser melting point fraction of jojoba oil maybe from 25:1 to 50:1. For example, the molar ratio of oleic acid topalmitoleic acid present within the lesser melting point fraction ofjojoba oil may be from 25:1 to 45:1, from 25:1 to 40:1, from 25:1 to35:1, from 25:1 to 30:1, from 30:1 to 50:1, from 30:1 to 45:1, from 30:1to 40:1, from 30:1 to 35:1, from 35:1 to 50:1, from 35:1 to 45:1, from35:1 to 40:1, from 40:1 to 50:1, from 40:1 to 45:1, or from 45:1 to50:1.

In embodiments, the water-based drilling fluid may be formulated to havespecific characteristics, such as increased viscosity and density. Forexample, the water-based drilling fluid may be formulated to have adensity in a range suitable to provide the necessary hydrostaticpressure to support the sidewalls of the wellbore and prevent fluids inthe formation from flowing into the wellbore. Additionally, thewater-based drilling fluid may be formulated to have viscosity in arange suitable to allow the water-based drilling fluid to be pumped downthrough the drill string while still capturing and conveying cuttingsfrom the bottom of the subterranean formation. To accomplish thesefunctions, the water-based drilling fluid may include one or moreadditives that are suitable for use in water-based drilling fluids. Theone or more additive may include alkalinity adjusters, viscosifiers,shale inhibitors, fluid loss control agents, weighting agents, orcombinations of these. In embodiments, the water-based drilling fluidmay include one or more additives in an amount of from 0.1 vol. % to 75vol. % relative to the total volume of the water-based drilling fluid.For example, the water-based drilling fluid may include one or moreadditives in an amount of from 0.1 vol. % to 60 vol. %, from 0.1 vol. %to 45 vol. %, from 0.1 vol. % to 30 vol. % from 0.1 vol. % to 15 vol. %,from 15 vol. % to 75 vol. %, from 15 vol. % to 60 vol. %, from 15 vol. %to 45 vol. %, from 15 vol. % to 30 vol. %, from 30 vol. % to 75 vol. %,from 30 vol. % to 60 vol. %, from 30 vol. % to 45 vol. %, from 45 vol. %to 75 vol. %, from 45 vol. % to 60 vol. %, or from 60 vol. % to 75 vol.% relative to the total volume of the water-based drilling fluid.

As stated previously in the present disclosure, the water-based drillingfluid may include an alkalinity adjuster. Alkalinity adjusters mayinclude alkaline compounds that may be included in water-based drillingfluids to buffer the pH of the water-based drilling fluid. Thealkalinity adjuster may react with gases, such as carbon dioxide orhydrogen sulfide, encountered by the water-based drilling fluid duringdrilling operations to prevent the gases from hydrolyzing components ofthe water-based drilling fluid. In embodiments, the alkalinity adjustermay include lime (calcium hydroxide or calcium oxide), soda ash (sodiumcarbonate), sodium hydroxide, potassium hydroxide, or combinations ofthese. The water-based drilling fluid may include an alkalinity adjusterin an amount sufficient to adjust the pH of the water-based drillingfluid to a desired level. In embodiments, the water-based drilling fluidmay include an alkalinity adjuster in an amount of from 0.1 vol. % to 75vol. % relative to the total volume of the water-based drilling fluid.For example, the water-based drilling fluid may include an alkalinityadjuster in an amount of from 0.1 vol. % to 60 vol. %, from 0.1 vol. %to 45 vol. %, from 0.1 vol. % to 30 vol. % from 0.1 vol. % to 15 vol. %,from 15 vol. % to 75 vol. %, from 15 vol. % to 60 vol. %, from 15 vol. %to 45 vol. %, from 15 vol. % to 30 vol. %, from 30 vol. % to 75 vol. %,from 30 vol. % to 60 vol. %, from 30 vol. % to 45 vol. %, from 45 vol. %to 75 vol. %, from 45 vol. % to 60 vol. %, or from 60 vol. % to 75 vol.% relative to the total volume of the water-based drilling fluid.

As stated previously in the present disclosure, in embodiments thewater-based drilling fluid may include a viscosifier, also referred toas a rheology modifier. Viscosifiers may impart non-Newtonian fluidrheology to the water-based drilling fluid, create a flat viscosityprofile of the water-based drilling fluid in annular flow, or both. Thismay facilitate the lifting and conveying of cuttings from the bottom ofthe subterranean formation to the surface during drilling of thesubterranean well. In embodiments, the viscosifier may includepolysaccharides, bentonite, polyacrylamides, polyanionic cellulose, orcombinations of these. For example, the viscosifier may include xanthangum, a polysaccharide also referred to as “XC polymer.” The water-baseddrilling fluid may include a viscosifier in an amount sufficient toimpart non-Newtonian fluid rheology to the water-based drilling fluid,create a flat viscosity profile of the water-based drilling fluid inannular flow, or both. In embodiments, the water-based drilling fluidmay include a viscosifier in an amount of from 0.1 vol. % to 75 vol. %relative to the total volume of the water-based drilling fluid. Forexample, the water-based drilling fluid may include a viscosifier in anamount of from 0.1 vol. % to 60 vol. %, from 0.1 vol. % to 45 vol. %,from 0.1 vol. % to 30 vol. % from 0.1 vol. % to 15 vol. %, from 15 vol.% to 75 vol. %, from 15 vol. % to 60 vol. %, from 15 vol. % to 45 vol.%, from 15 vol. % to 30 vol. %, from 30 vol. % to 75 vol. %, from 30vol. % to 60 vol. %, from 30 vol. % to 45 vol. %, from 45 vol. % to 75vol. %, from 45 vol. % to 60 vol. %, or from 60 vol. % to 75 vol. %relative to the total volume of the water-based drilling fluid. Ininstances where a polymer-based viscosifier is used, the water-baseddrilling fluid may further include a thermal stabilizer, such as sodiumsulfite, which may prevent the thermal degradation of the viscosifier atincreased temperatures, such as those downhole of the wellbore. Inembodiments, the water-based drilling fluid may include a thermalstabilizer in an amount of from 0.1 vol. % to 10 vol. % relative to thetotal volume of the water-based drilling fluid. For example, thewater-based drilling fluid may include a thermal stabilizer in an amountof from 0.1 vol. % to 8 vol. %, from 0.1 vol. % to 6 vol. %, from 0.1vol. % to 4 vol. % from 0.1 vol. % to 2 vol. %, from 2 vol. % to 10 vol.%, from 2 vol. % to 8 vol. %, from 2 vol. % to 6 vol. %, from 2 vol. %to 4 vol. %, from 4 vol. % to 10 vol. %, from 4 vol. % to 8 vol. %, from4 vol. % to 6 vol. %, from 6 vol. % to 10 vol. %, from 6 vol. % to 8vol. %, or from 8 vol. % to 10 vol. % relative to the total volume ofthe water-based drilling fluid.

As stated previously in the present disclosure, the water-based drillingfluid may include a shale inhibitor. Shale inhibitors, also referred toas clay stabilizers or swelling inhibitors, may prevent the swelling andhydration of water-sensitive subterranean formation, such as shaleformations. Shale inhibitors may attach to the surface of thesubterranean formation and lend stability to the formation exposed tothe water-based drilling fluid as well as prevent cuttings fromdispersing into finer particles. The shale inhibitor may include sodiumchloride, potassium chloride, potassium carbonate, potassium lignite,calcium chloride, sodium asphalt sulfonate (commercially available asSOLTEX® from Chevron Phillips Chemical Company), or combinations ofthese. The water-based drilling fluid may include a shale inhibitor inan amount sufficient to prevent the swelling and hydration of thesubterranean formation. In embodiments, the water-based drilling fluidmay include a shale inhibitor in an amount of from 0.1 vol. % to 75 vol.% relative to the total volume of the water-based drilling fluid. Forexample, the water-based drilling fluid may include a shale inhibitor inan amount of from 0.1 vol. % to 60 vol. %, from 0.1 vol. % to 45 vol. %,from 0.1 vol. % to 30 vol. % from 0.1 vol. % to 15 vol. %, from 15 vol.% to 75 vol. %, from 15 vol. % to 60 vol. %, from 15 vol. % to 45 vol.%, from 15 vol. % to 30 vol. %, from 30 vol. % to 75 vol. %, from 30vol. % to 60 vol. %, from 30 vol. % to 45 vol. %, from 45 vol. % to 75vol. %, from 45 vol. % to 60 vol. %, or from 60 vol. % to 75 vol. %relative to the total volume of the water-based drilling fluid.

As stated previously in the present disclosure, in embodiments thewater-based drilling fluid may include a fluid loss control agent. Fluidloss control agents may reduce or prevent the leakage of the liquidphase of the water-based drilling fluid into the subterranean formation.This leakage may result in an undesirable buildup of solid materialpresent in the water-based drilling fluid, damage to the subterraneanformation, or both. In embodiments, the fluid loss control agent mayinclude starch, carboxymethyl starch, carboxymethylcellulose, sodiumasphalt sulfonate (commercially available as SOLTEX® from ChevronPhillips Chemical Company), or combinations of these. The water-baseddrilling fluid may include a fluid loss control agent in an amountsufficient to the reduce or prevent the leakage of the liquid phase ofthe water-based drilling fluid into the subterranean formation. Inembodiments, the water-based drilling fluid may include a fluid losscontrol agent in an amount of from 0.1 vol. % to 75 vol. % relative tothe total volume of the water-based drilling fluid. For example, thewater-based drilling fluid may include a fluid loss control agent in anamount of from 0.1 vol. % to 60 vol. %, from 0.1 vol. % to 45 vol. %,from 0.1 vol. % to 30 vol. % from 0.1 vol. % to 15 vol. %, from 15 vol.% to 75 vol. %, from 15 vol. % to 60 vol. %, from 15 vol. % to 45 vol.%, from 15 vol. % to 30 vol. %, from 30 vol. % to 75 vol. %, from 30vol. % to 60 vol. %, from 30 vol. % to 45 vol. %, from 45 vol. % to 75vol. %, from 45 vol. % to 60 vol. %, or from 60 vol. % to 75 vol. %relative to the total volume of the water-based drilling fluid.

As stated previously in the present disclosure, in embodiments thewater-based drilling fluid may include a weighting agent. Weightingagents may include finely divided solid particles that may be dispersedin the water-based drilling fluid. Weighting agents may increase thedensity of the water-based drilling fluid to support the sidewalls ofthe wellbore. Weighting agents may also increase the hydrostaticpressure of the water-based drilling fluid to reduce or prevent fluidspresent in the subterranean formation from flowing into the wellbore. Inembodiments, the weighting agent may include barite, hematite, calciumcarbonate, siderite, ilmenite, or combinations of these. In embodiments,the water-based drilling fluid may include a weighting agent in anamount sufficient for the water-based drilling fluid to achieve adensity of from 50 pounds per cubic foot (pcf) to 150 pcf, as measuredin accordance with the American Petroleum Institute (API) recommendedpractice 13B-1. For example, the water-based drilling fluid may includea weighting agent in an amount sufficient for the water-based drillingfluid to achieve a density of from 50 pcf to 125 pcf, from 50 pcf to 100pcf, from 50 pcf to 75 pcf, from 75 pcf to 150 pcf, from 75 pcf to 125pcf, from 75 pcf to 100 pcf, from 100 pcf to 150 pcf, from 100 pcf to125 pcf, or from 125 pcf to 150 pcf. In embodiments, the water-baseddrilling fluid may include a weighting agent in an amount of from 0.1vol. % to 75 vol. % relative to the total volume of the water-baseddrilling fluid. For example, the water-based drilling fluid may includea weighting agent in an amount of from 0.1 vol. % to 60 vol. %, from 0.1vol. % to 45 vol. %, from 0.1 vol. % to 30 vol. % from 0.1 vol. % to 15vol. %, from 15 vol. % to 75 vol. %, from 15 vol. % to 60 vol. %, from15 vol. % to 45 vol. %, from 15 vol. % to 30 vol. %, from 30 vol. % to75 vol. %, from 30 vol. % to 60 vol. %, from 30 vol. % to 45 vol. %,from 45 vol. % to 75 vol. %, from 45 vol. % to 60 vol. %, or from 60vol. % to 75 vol. % relative to the total volume of the water-baseddrilling fluid.

The present disclosure is also directed to the use of the water-baseddrilling fluid in drilling operations, such as drilling a subterraneanwell. Accordingly, methods for drilling a subterranean well may includeoperating a drill in a subterranean formation in the presence of awater-based drilling fluid. The water-based drilling fluid may be inaccordance with any of the embodiments previously described in thepresent disclosure. In embodiments, the water-based drilling fluid maybe introduced into the subterranean formation. Introducing thewater-based drilling fluid may involve injecting the drilling fluid intothe subterranean formation. In embodiments, the drilling fluid may beinjected through a drill string of the drill to a drill bit. Inembodiments, the subterranean formation may be a subterranean well. Thewater-based drilling fluid may at least be partially circulated withinthe subterranean formation. Recirculating the water-based drilling fluidmay allow the water-based drilling fluid to cool and lubricate the drillbit and to lift cuttings away from the drill bit, carrying the cuttingsupwards to the surface to clean the wellbore. The water-based drillingfluid may additionally provide hydrostatic pressure to support thesidewalls of the wellbore and prevent the sidewalls from collapsing ontothe drill string.

Further embodiments of the present disclosure may relate to particularmethods of preparing the water-based drilling fluid. The method mayinclude processing jojoba oil to produce the lesser melting pointfraction of jojoba, as described previously in the present disclosure.In embodiments, the processing of jojoba oil may include screening,chilling, filtering, or combinations of these. The screening of jojobaoil may include passing the jojoba oil through a sieve. In embodiments,the sieve may have an average pore size less than or equal to 100microns. For example, the sieve may have an average pore size less thanor equal to 90 microns, less than or equal to 80 microns, less than orequal to 70 microns, less than or equal to 60 microns, or less than orequal to 50 microns. The chilling of jojoba oil may include reducing thetemperature of jojoba oil to a temperature sufficient to solidify atleast a fraction of the jojoba oil. In embodiments, the temperature ofthe jojoba oil may be reduced to less than or equal to 15° C. Forexample, the temperature of the jojoba oil may be reduced to less thanor equal to 12° C., less than or equal to 9° C., less than or equal to6° C., less than or equal to 3° C., or less than or equal to 0° C. Thefiltering of jojoba oil may include separating a liquid phase of thejojoba oil from a solid phase of the jojoba oil. The method may alsoinclude mixing the lesser melting point fraction of jojoba oil with anaqueous base fluid and one or more additives. The aqueous base fluid,the one or more additives, and the lesser melting point fraction ofjojoba oil may each be provided in accordance with any of theembodiments previously described in the present disclosure.

EXAMPLES

The various embodiments of water-based drilling fluid compositions willbe further clarified by the following example. The example isillustrative in nature, and should not be understood to limit thesubject matter of the present disclosure.

Example 1—Lubricity of Water-Based Drilling Fluids (without AddedLubricant)

To observe the effects of the presently disclosed lubricant blend inreducing the coefficient of friction of a water-based drilling fluid,two water-based drilling fluids were prepared. The first water-baseddrilling fluid (Drilling Fluid 1) was prepared by mixing 340 milliliters(ml) of water, 0.25 grams (g) of soda ash, and 25 g of bentonite. Thesecond water-based drilling fluid (Drilling Fluid 2) was prepared bymixing 332 ml of water, 0.3 g of soda ash, 6 g of bentonite, 3 g ofpolyanionic cellulose, 1 g of xanthan gum, 20 g of potassium chloride, 3g of sodium asphalt sulfonate, and 1 g of sodium sulfite.

Drilling Fluid 1 and Drilling Fluid 2 were then each tested for abaseline coefficient of friction value without an added lubricant blend.A portion of each water-based drilling fluid was loaded into thelubricity tester, commercially available as “EP and Lubricity Tester”from OFITE, and a test block was subjected to 150 inch-pounds of torquewithin the water-based drilling fluid for 5 minutes. The composition andmeasured coefficient of friction of both Drilling Fluid 1 and DrillingFluid 2 are provided in Table 1.

TABLE 1 Drilling Fluid 1 Drilling Fluid 2 Water (ml) 340 332 Soda Ash(g) 0.25 0.3 Bentonite (g) 25 6 Polyanionic Cellulose (g) — 3 XanthanGum (g) — 1 Potassium Chloride (g) — 20 Sodium Asphalt Sulfonate (g) — 3Sodium Sulfite (g) — 1 Coefficient of Friction 0.45 0.22

Example 2—Production of Lubricant Blend

To prepare a lubricant blend of the present disclosure, seeds of thejojoba plant were crushed and pressed to produce jojoba oil. The jojobaoil was then collected and screened using a sieve having an average poresize less than 74 microns to separate any particulate material largerthan 74 microns from the jojoba oil. The jojoba oil was then placed in achilling chamber until the jojoba oil reached a temperature of 15° C.and a particulate cloud containing solidified fatty acids andparticulate material small than 74 microns had formed. The jojoba oilwas then pressure filtered using a hardened filter paper having anaverage pore size of 5 microns and an average pressure of from 10 poundsper square inch (psi) to 20 psi to separate the particulate cloud fromthe liquid jojoba oil. The screening, chilling, and filtering of theliquid jojoba oil were then conducted two additional times, producingthe lubricant blend.

Example 3—Lubricity of Water-Based Drilling Fluids (with AddedLubricant)

Separate samples of both Drilling Fluid 1 and Drilling Fluid 2, asprepared in Example 1, were loaded with the lubricant blend, as preparedin Example 2, diesel oil, and mineral oil. The resulting water-baseddrilling fluids each included 3 vol. % of a lubricant. A portion of eachwater-based drilling fluid was loaded into the lubricity tester,commercially available as “EP and Lubricity Tester” from OFITE, and atest block was subjected to 150 inch-pounds of torque within thewater-based drilling fluid for 5 minutes. The coefficient of frictionmeasurements for each water-based drilling fluid are provided in Table2.

TABLE 2 No Lubricant Diesel Mineral Lubricant Blend Oil Oil Coefficientof Friction Drilling Fluid 1 0.45 0.09 0.13 0.12 Drilling Fluid 2 0.220.13 0.14 0.14

As shown by the results provided in Table 2, the inclusion of 3 vol. %of the disclosed lubricant blend resulted in an 80 percent (%) decreasein the coefficient of friction of Drilling Fluid 1. This decrease in thecoefficient of friction was also greater than the decrease achieved byeither of the conventional lubricants, diesel oil and mineral oil.Similarly, the inclusion of 3 vol. % of the disclosed lubricant blendalso resulted in a 41% decrease in the coefficient of friction ofDrilling Fluid 2 compared to the 36% decrease achieved by theconventional lubricants. This indicates that the disclosed lubricantblend is capable of sufficiently decreasing the coefficient of frictionof a water-based drilling fluid. Additionally, this indicates thatwater-based drilling fluids that include the lubricant blend may have adecreased coefficient of friction and, as a result, an increasedlubricity when compared to water-based drilling fluids that includeconventional lubricants.

It will be apparent to those skilled in the art that variousmodifications and variations can be made without departing from thespirit or scope of the disclosure. Since modifications, combinations,sub-combinations and variations of the disclosed embodimentsincorporating the spirit and substance of the disclosure may occur topersons skilled in the art, the scope of the disclosure should beconstrued to include everything within the scope of the appended claimstheir equivalents.

In a first aspect of the present disclosure, a water-based drillingfluid may include an aqueous base fluid, one or more additives, and alubricant blend including at least oleic acid and palmitoleic acid. Thesum of the volume percent of the oleic acid and palmitoleic acid may befrom 0.1 vol. % to 10 vol. % of the total volume of the water-baseddrilling fluid.

A second aspect of the present disclosure may include the first aspectwhere the molar ratio of oleic acid to palmitoleic acid may be from 25:1to 50:1.

A third aspect of the present disclosure may include either of the firstor second aspects where the lubricant blend includes a lesser meltingpoint fraction of jojoba oil. At least 90% of the lesser melting pointfraction of jojoba oil may have a melting point less than or equal to15° C.

A fourth aspect of the present disclosure may include any of the firstthrough third aspects where the one or more additives include at leastone of an alkalinity adjuster, a viscosifier, a shale inhibitor, a fluidloss control agent, or a weighting agent.

A fifth aspect of the present disclosures may include any of the firstthrough fourth aspects where the water-based drilling fluid includes theaqueous base fluid in an amount of from 25 vol. % to 99 vol. % relativeto the total volume of the water-based drilling fluid.

A sixth aspect of the present disclosures may include any of the firstthrough fifth aspects where the water-based drilling fluid includes theone or more additives in an amount of from 0.1 vol. % to 75 vol. %relative to the total volume of the water-based drilling fluid.

In a seventh aspect of the present disclosure, a water-based drillingfluid may include an aqueous base fluid, one or more additives, and alesser melting point fraction of jojoba oil in an amount of from 0.1vol. % to 10 vol. % relative to the total volume of the water-baseddrilling fluid. At least 90% of the lesser melting point fraction ofjojoba oil may have a melting point less than or equal to 15° C.

An eighth aspect of the present disclosure may include the seventhaspect where the lesser melting point fraction of jojoba oil includes atleast oleic acid and palmitoleic acid.

A ninth aspect of the present disclosure may include the eighth aspectwhere the lesser melting point fraction of jojoba oil includes oleicacid in an amount of from 75 vol. % to 99 vol. % relative to the totalvolume of the lesser melting point fraction of jojoba oil.

A tenth aspect of the present disclosure may include either of theeighth or ninth aspects where the lesser melting point fraction ofjojoba oil includes palmitoleic acid in an amount of from 1 vol. % to 25vol. % relative to the total volume of the lesser melting point fractionof jojoba oil.

An eleventh aspect of the present disclosure may include may include anyof the eighth through tenth aspects where the molar ratio of oleic acidto palmitoleic acid may be from 25:1 to 50:1.

A twelfth aspect of the present disclosure may include any of theseventh through eleventh aspects where the one or more additives includeat least one of an alkalinity adjuster, a viscosifier, a shaleinhibitor, a fluid loss control agent, or a weighting agent.

A thirteenth aspect of the present disclosure may include any of theseventh through twelfth aspects where the water-based drilling fluidincludes the aqueous base fluid in an amount of from 25 vol. % to 99vol. % relative to the total volume of the water-based drilling fluid.

A fourteenth aspect of the present disclosure may include any of theseventh through thirteenths aspects where the water-based drilling fluidincludes the one or more additives in an amount of from 0.1 vol. % to 75vol. % relative to the total volume of the water-based drilling fluid.

In a fifteenth aspect of the present disclosure, a method for drilling asubterranean well may include operating a drill in a subterraneanformation in the presence of a water-based drilling fluid. Thewater-based drilling fluid may include an aqueous base fluid, one ormore additives, and a lubricant blend including at least oleic acid andpalmitoleic acid. The sum of the volume percent of the oleic acid andpalmitoleic acid may be from 0.1 vol. % to 10 vol. % of the total volumeof the water-based drilling fluid.

A sixteenth aspect of the present disclosure may include the fifteenthaspect where the molar ratio of oleic acid to palmitoleic acid may befrom 25:1 to 50:1.

A seventeenth aspect of the present disclosure may include either of thefifteenth or sixteenth aspects where the lubricant blend includes alesser melting point fraction of jojoba oil. At least 90% of the lessermelting point fraction of jojoba oil may have a melting point less thanor equal to 15° C.

An eighteenth aspect of the present disclosure may include any of thefifteenth through seventeenth aspects where the one or more additivesinclude at least one of an alkalinity adjuster, a viscosifier, a shaleinhibitor, a fluid loss control agent, or a weighting agent.

A nineteenth aspect of the present disclosure may include any of thefifteenth through eighteenth aspects where the water-based drillingfluid includes the aqueous base fluid in an amount of from 25 vol. % to99 vol. % relative to the total volume of the water-based drillingfluid.

A twentieth aspect of the present disclosure may include any of thefifteenth through nineteenth aspects where the water-based drillingfluid includes the one or more additives in an amount of from 0.1 vol. %to 75 vol. % relative to the total volume of the water-based drillingfluid.

In a twenty-first aspect of the present disclosure, a method fordrilling a subterranean well may include operating a drill in asubterranean formation in the presence of a water-based drilling fluid.The water-based drilling fluid may include an aqueous base fluid, one ormore additives, and a lesser melting point fraction of jojoba oil in anamount of from 0.1 vol. % to 10 vol. % relative to the total volume ofthe water-based drilling fluid. At least 90% of the lesser melting pointfraction of jojoba oil may have a melting point less than or equal to15° C.

A twenty-second aspect of the present disclosure may include thetwenty-first aspect where the lesser melting point fraction of jojobaoil includes at least oleic acid and palmitoleic acid.

A twenty-third aspect of the present disclosure may include thetwenty-second aspect where the lesser melting point fraction of jojobaoil includes oleic acid in an amount of from 75 vol. % to 99 vol. %relative to the total volume of the lesser melting point fraction ofjojoba oil.

A twenty-fourth aspect of the present disclosure may include either ofthe twenty-second or twenty-third aspects where the lesser melting pointfraction of jojoba oil includes palmitoleic acid in an amount of from 1vol. % to 25 vol. % relative to the total volume of the lesser meltingpoint fraction of jojoba oil.

A twenty-fifth aspect of the present disclosure may include any of thetwenty-second through twenty-fourth aspects where the molar ratio ofoleic acid to palmitoleic acid may be from 25:1 to 50:1.

A twenty-sixth aspect of the present disclosure may include any of thetwenty-first through twenty-fifth aspects where the one or moreadditives include at least one of an alkalinity adjuster, a viscosifier,a shale inhibitor, a fluid loss control agent, or a weighting agent.

A twenty-seventh aspect of the present disclosure may include any of thetwenty-first through twenty-sixth aspects where the water-based drillingfluid includes the aqueous base fluid in an amount of from 25 vol. % to99 vol. % relative to the total volume of the water-based drillingfluid.

A twenty-eighth aspect of the present disclosure may include any of thetwenty-first through twenty-seventh aspects where the water-baseddrilling fluid includes the one or more additives in an amount of from0.1 vol. % to 75 vol. % relative to the total volume of the water-baseddrilling fluid.

In a twenty-ninth aspect of the present disclosure, a method ofproducing a water-based drilling fluid may include processing jojoba oilto produce a lesser melting point fraction of jojoba oil and mixing anaqueous base fluid, one or more additives, and the lesser melting pointfraction of jojoba oil to produce the water-based drilling fluid. Atleast 90% of the lesser melting point fraction of jojoba oil may have amelting point less than or equal to 15° C.

A thirtieth aspect of the present disclosure may include thetwenty-ninth aspect further including introducing the water-baseddrilling fluid into a subterranean formation.

A thirty-first aspect of the present disclosure may include thethirtieth aspect further including operating a drill in the subterraneanformation in the presence of the water-based drilling fluid.

It should now be understood that various aspects of the water-baseddrilling fluid compositions and methods for drilling subterranean wellsare described and such aspects may be utilized in conjunction withvarious other aspects.

It is noted that one or more of the following claims utilize the term“where” as a transitional phrase. For the purposes of defining thepresent disclosure, it is noted that this term is introduced in theclaims as an open-ended transitional phrase that is used to introduce arecitation of a series of characteristics of the structure and should beinterpreted in like manner as the more commonly used open-ended preambleterm “comprising.”

It should be understood that any two quantitative values assigned to aproperty may constitute a range of that property, and all combinationsof ranges formed from all stated quantitative values of a given propertyare contemplated in this disclosure.

Having described the subject matter of the present disclosure in detailand by reference to specific embodiments, it is noted that the variousdetails described in this disclosure should not be taken to imply thatthese details relate to elements that are essential components of thevarious embodiments described in this disclosure. Rather, the appendedclaims should be taken as the sole representation of the breadth of thepresent disclosure and the corresponding scope of the variousembodiments described in this disclosure. Further, it will be apparentthat modifications and variations are possible without departing fromthe scope of the appended claims.

1. A water-based drilling fluid comprising: an aqueous base fluid; oneor more additives; and a lubricant blend comprising at least oleic acidand palmitoleic acid, where all of the fatty acids in the water-baseddrilling fluid are encompassed in the lubricant blend; where the sum ofthe volume percent of the oleic acid and palmitoleic acid is from 0.1vol. % to 10 vol. % of the total volume of the water-based drillingfluid; and where at least 90% of the fatty acids in the lubricant blendhave a melting point less than or equal to 15° C.
 2. The water-baseddrilling fluid of claim 1, where the molar ratio of oleic acid topalmitoleic acid is from 25:1 to 50:1.
 3. The water-based drilling fluidof claim 1, where the lubricant blend comprises a lesser melting pointfraction of jojoba oil, where at least 90% of the lesser melting pointfraction of jojoba oil has a melting point less than or equal to 15° C.4. The water-based drilling fluid of claim 1, where the water-baseddrilling fluid comprises the aqueous base fluid in an amount of from 25vol. % to 99 vol. % relative to the total volume of the water-baseddrilling fluid.
 5. The water-based drilling fluid of claim 1, where thewater-based drilling fluid comprises the one or more additives in anamount of from 0.1 vol. % to 75 vol. % relative to the total volume ofthe water-based drilling fluid. 6-12. (canceled)
 13. A method ofdrilling a subterranean well, the method comprising: operating a drillin a subterranean formation in the presence of a water-based drillingfluid, where the water-based drilling fluid comprises: an aqueous basefluid; one or more additives; and a lubricant blend comprising at leastoleic acid and palmitoleic acid, where all of the fatty acids in thewater-based drilling fluid are encompassed in the lubricant blend; wherethe sum of the volume percent of the oleic acid and palmitoleic acid isfrom 0.1 vol. % to 10 vol. % of the total volume of the water-baseddrilling fluid; and where at least 90% of the fatty acids in thelubricant blend have a melting point less than or equal to 15° C. 14.The method of claim 13, where the molar ratio of oleic acid topalmitoleic acid is from 25:1 to 50:1.
 15. The method of claim 13, wherethe lubricant blend comprises a lesser melting point fraction of jojobaoil, where at least 90% of the lesser melting point fraction of jojobaoil has a melting point less than or equal to 15° C. 16-17. (canceled)18. A method of producing a water-based drilling fluid, the methodcomprising: processing jojoba oil to produce a lesser melting pointfraction of jojoba oil, where at least 90% of the lesser melting pointfraction of jojoba oil has a melting point less than or equal to 15° C.;and mixing an aqueous base fluid, one or more additives, and the lessermelting point fraction of jojoba oil to produce the water-based drillingfluid.
 19. The method of claim 18, further comprising introducing thewater-based drilling fluid into a subterranean formation.
 20. The methodof claim 19, further comprising operating a drill in the subterraneanformation in the presence of the water-based drilling fluid.
 21. Thewater-based drilling fluid of claim 1, where the lubricant blend issubstantially free of solids at a temperature of less than or equal to15° C.